:right-sidebar: True

DeviceMonitor
===================================================================

.. currentmodule:: gi.repository.Gst


.. versionadded:: 1.4




.. class:: DeviceMonitor(**properties: ~typing.Any)
   :no-contents-entry:


Superclasses: :class:`~gi.repository.Gst.Object`, :class:`~gi.repository.GObject.InitiallyUnowned`, :class:`~gi.repository.GObject.Object`





Applications should create a :obj:`~gi.repository.Gst.DeviceMonitor` when they want
to probe, list and monitor devices of a specific type. The
:obj:`~gi.repository.Gst.DeviceMonitor` will create the appropriate
:obj:`~gi.repository.Gst.DeviceProvider` objects and manage them. It will then post
messages on its :obj:`~gi.repository.Gst.Bus` for devices that have been added and
removed.

The device monitor will monitor all devices matching the filters that
the application has set.

The basic use pattern of a device monitor is as follows:


.. code-block::
    :dedent:

      static gboolean
      my_bus_func (GstBus * bus, GstMessage * message, gpointer user_data)
      {
         GstDevice *device;
         gchar *name;

         switch (GST_MESSAGE_TYPE (message)) {
           case GST_MESSAGE_DEVICE_ADDED:
             gst_message_parse_device_added (message, &device);
             name = gst_device_get_display_name (device);
             g_print("Device added: %s\n", name);
             g_free (name);
             gst_object_unref (device);
             break;
           case GST_MESSAGE_DEVICE_REMOVED:
             gst_message_parse_device_removed (message, &device);
             name = gst_device_get_display_name (device);
             g_print("Device removed: %s\n", name);
             g_free (name);
             gst_object_unref (device);
             break;
           default:
             break;
         }

         return G_SOURCE_CONTINUE;
      }

      GstDeviceMonitor *
      setup_raw_video_source_device_monitor (void) {
         GstDeviceMonitor *monitor;
         GstBus *bus;
         GstCaps *caps;

         monitor = gst_device_monitor_new ();

         bus = gst_device_monitor_get_bus (monitor);
         gst_bus_add_watch (bus, my_bus_func, NULL);
         gst_object_unref (bus);

         caps = gst_caps_new_empty_simple ("video/x-raw");
         gst_device_monitor_add_filter (monitor, "Video/Source", caps);
         gst_caps_unref (caps);

         gst_device_monitor_start (monitor);

         return monitor;
      }


Constructors
------------

.. rst-class:: interim-class

.. class:: DeviceMonitor
   :no-index:


   .. classmethod:: new() -> ~gi.repository.Gst.DeviceMonitor

      Create a new :obj:`~gi.repository.Gst.DeviceMonitor`


      .. versionadded:: 1.4












Methods
-------

.. rst-class:: interim-class

.. class:: DeviceMonitor
   :no-index:


   .. method:: add_filter(classes: str | None = None, caps: ~gi.repository.Gst.Caps | None = None) -> int

      Adds a filter for which :obj:`~gi.repository.Gst.Device` will be monitored, any device that matches
      all these classes and the :obj:`~gi.repository.Gst.Caps` will be returned.

      If this function is called multiple times to add more filters, each will be
      matched independently. That is, adding more filters will not further restrict
      what devices are matched.

      The :obj:`~gi.repository.Gst.Caps` supported by the device as returned by :func:`~gi.repository.Gst.Device.get_caps` are
      not intersected with caps filters added using this function.

      Filters must be added before the :obj:`~gi.repository.Gst.DeviceMonitor` is started.


      .. versionadded:: 1.4





      :param classes: device classes to use as filter or :const:`None` for any class

      :param caps: the :obj:`~gi.repository.Gst.Caps` to filter or :const:`None` for ANY




   .. method:: get_bus() -> ~gi.repository.Gst.Bus

      Gets the :obj:`~gi.repository.Gst.Bus` of this :obj:`~gi.repository.Gst.DeviceMonitor`


      .. versionadded:: 1.4








   .. method:: get_devices() -> list[~gi.repository.Gst.Device] | None

      Gets a list of devices from all of the relevant monitors. This may actually
      probe the hardware if the monitor is not currently started.


      .. versionadded:: 1.4








   .. method:: get_providers() -> list[str]

      Get a list of the currently selected device provider factories.

      This


      .. versionadded:: 1.6








   .. method:: get_show_all_devices() -> bool

      Get if ``monitor`` is currently showing all devices, even those from hidden
      providers.


      .. versionadded:: 1.6








   .. method:: remove_filter(filter_id: int) -> bool

      Removes a filter from the :obj:`~gi.repository.Gst.DeviceMonitor` using the id that was returned
      by :func:`~gi.repository.Gst.DeviceMonitor.add_filter`.


      .. versionadded:: 1.4





      :param filter_id: the id of the filter




   .. method:: set_show_all_devices(show_all: bool) -> None

      Set if all devices should be visible, even those devices from hidden
      providers. Setting ``show_all`` to true might show some devices multiple times.


      .. versionadded:: 1.6





      :param show_all: show all devices




   .. method:: start() -> bool

      Starts monitoring the devices, one this has succeeded, the
      :const:`~gi.repository.Gst.MessageType.DEVICE_ADDED` and :const:`~gi.repository.Gst.MessageType.DEVICE_REMOVED` messages
      will be emitted on the bus when the list of devices changes.


      .. versionadded:: 1.4








   .. method:: stop() -> None

      Stops monitoring the devices.


      .. versionadded:: 1.4












Properties
----------

.. rst-class:: interim-class

.. class:: DeviceMonitor
   :no-index:
   

   .. attribute:: props.show_all
      :type: bool

      The type of the None singleton.















Fields
------

.. rst-class:: interim-class

.. class:: DeviceMonitor
   :no-index:
   

   .. attribute:: parent

      The parent :obj:`~gi.repository.Gst.Object` structure






   .. attribute:: priv